The present invention relates generally to a method and system for use in the positive and secure positioning of fractured bones. More specifically, the present invention relates to double plate assembly for use in repairing bone fractures that demonstrates improved stability when buttressing fractures that exhibit complex articular patterns and comminution.
The human skeleton consists of 206 individual bones that cooperate to perform a variety of important functions such as support, movement, protection, storage of minerals, and formation of blood cells. The bones within the skeleton are generally grouped into two categories, the axial skeleton and the appendicular skeleton. The axial skeleton includes 80 bones that make up the body's center of gravity and the appendicular skeleton includes the remaining 126 bones that make up the body's appendages.
When a person suffers a bone injury such as a bone fracture, it is important that the fractured bone be repaired promptly and properly. When such a fracture is severe enough, repair often requires remedies that may include surgical intervention. The typical treatment for a fractured bone involves the use of a fixation device that serves to reinforce the fractured bone and keep the adjacent portions of the bone aligned during healing. A wide variety of fixation devices are employed to maintain bone alignment. Further, these bone fixation devices take a variety of forms, including external devices such as casts and internal devices such as bone plates and screws. As can be appreciated by one skilled in the art, bone repairs employing external devices are minimally invasive, allowing reduction and fixation of simple fractures from outside the body. In contrast, bone plates are internal devices that mount directly to bone to span and support the fracture and require a fairly invasive process for placement and installation thereof.
While most bones in the skeleton are susceptible to injury or fracture, the repair method used depends on the location of the bone and the proximity of the break to a joint. Further, some bones require a more precise repair as compared to others in order to insure stability of the joint. For example, the radius is one of two long bones found in the human forearm. Distal fractures of the radius are a common result of forward falls, with the palms facing downward, particularly among the elderly. In such falls, force exerted on the distal radius at impact frequently produces dorsal displacement of one or more bone fragments created distal to the fracture site. Unfortunately, internal fixation of such dorsally displaced bone fragments using bone plates has proved problematic. Using dorsal fixation, a surgeon may apply a reducing force on the fracture by attaching a bone plate to the dorsal side of the radius. However, unless the bone plate has a very low profile, dorsal tendons overlying the bone plate may rub against it, producing tendon irritation or even tendon rupture.
Alternatively, fixation may be performed volarly. In this approach, a surgeon may attach a bone plate to the volar side of the radius. The volar side of the radius may be more accessible surgically and defines a distal pocket in which the distal portion of the bone plate may be disposed. Accordingly, the bone plate may be less obtrusive and its placement at this location may produce less tendon irritation, even if the bone plate is thicker and sturdier. However, while volar fixation provides advantages as compared to dorsal fixation, there are settings where a single volar or dorsal implant does not provide enough stability to provide reliable support for the bony structures. This is particularly problematic in elderly patients that generally have poor quality bone or in high-speed injuries with highly comminuted fracture patterns. In these situations, bone screws used for fastening the plate in place are inserted through openings in the plate. The difficulty is that when the screws are installed into the distal radius, they may not find sufficient bone structure to hold distal bone fragments in position against the bone plate. In addition, it should be appreciated by one skilled in the art that this scenario is not unique to distal radius fractures. It also happens, for example, in distal humerus, proximal olecranon, distal ulna, proximal tibia and distal tibia (pilon) injuries when in certain situations it is necessary to use double plates in order to provide the best mechanical construct.
Therefore there is a need for an alternative strategy for reducing and fixing bone fractures that exhibit complex articular patterns and comminution. There is a further need for a method and system that retains the fractured portions of bone in a rigid structure that does not rely on fastening directly to the bone itself for reducing and fixing the bone fracture